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At least 19 recordsLinked to original sources
PubMed1976

A study of the isolation of Corynebacterium diphtheria from clinical cases of diphtheria.

Throat swabs from 1000 clinical cases of diphtheria were studied for isolation of C. diphtheria; only 21.4% were found to be positive. Most of the cases were between 1 to 4 years of age followed by 5 to 8 years. No cases were found below 8 months of age. The throat swabs taken from another 22 clinical diphtheria patients were immediately cultured at patients bed side and 63.6% were found to be positive for C. diphtheria. Time between the collection and plating the specimen was considered to be one of the main factors in the variation of the percentage isolation of C. diphtheria. From all KLB positive cases on direct smear, C. diphtheria could not be isolated on culture. Also, from all cases having definite patch(es) over tonsil(s), C. diphtheria could not be isolated. All strains were found to be sensitive against commonly used antibiotics.

Age Factors↗
PubMed1979

Diphtheria toxin-binding glycoproteins on hamster cells: candidates for diphtheria toxin receptors.

Diphtheria toxin-binding glycoproteins of high molecular weight (greater than 100,000) were identified on the surface of lymph node and thymus cells from hamsters, a diphtheria toxin-sensitive species. These diphtheria toxin-binding glycoproteins also interacted with CRM197 protein, which possesses toxin-blocking activity, but not with diphtheria toxoid, fragment A of diphtheria toxin, or cholera toxin, all of which lack toxin-blocking activity. These observations are consistent with the hypothesis that the detected diphtheria toxin-binding glycoproteins are involved in intoxication of cells by this toxin and possibly serve as the plasma membrane receptors for diphtheria toxin.

Animals↗
PubMed1975

Skin infections and the epidemiology of diphtheria: acquisition and persistence of C diphtheriae infections.

Acquisition and persistence of C. diphtheriae infections of skin lesions and of the respiratory tract were observed in households exposed to C. diphtheriae carriers in a community experiencing a diphtheria outbreak and in households in two communities free of the disease. Acquisition of C. diphtheriae was more frequent in epidemic households, apparently due to a greater frequency of respiratory tract acquisition. Skin lesion acquisition was constant in both situations. The pattern of persistence appeared to be the same in both types of households, although skin lesion C. diphtheriae infections had a greater tendency to persist than respiratory tract infections. Acquisition occurred more frequently following exposure to a skin lesion C. diphtheriae carrier than following a respiratory carrier exposure.

Carrier State↗
PubMed1975

The role of cutaneous diphtheria infections in a diphtheria epidemic.

Twenty-four people with diptheria and 48 carriers were found in an isolated, circumscribed, rural area during a one-month period. Four patients had cutaneous lesions, which were similar to those of typical impetigo, form which Corynebacterium diptheriae was isolated. These cases constituted an epidemiologic focus from which the other cases were infected. Ten of 52 classroom contacts of two patients with skin infections harbored C. diphtheriae in the pharynx, while only eight of 132 classroom contacts of eight respiratory cases were similarly infected. Respiratory carriage of C. diphtheriae in five of 12 Head start classroom contacts of another patient with cutaneous infection with C. diptheriae in the classroom situation. A tendency toward greater environmental contamination by cutaneous diphtheria than by respiratory diptheria might be related to the greater contagiousness cases.

Adolescent↗
PubMed1975

[The effect of neuraminidase of C. diphtheriae on the functional capacity of the peritoneal exudate cells of guinea pigs to diphtheria bacilli].

A study was made of the effect of neuraminidase preparation containing no diphtheria toxin admixtures and hyaluronidase on the phagocytic activity of macrophages. Neuraminidase produced a stimulating effect on the cells of the developing macrophage culture. The macrophages treated with the enzyme increased their capacity to digestion of nontoxigenic diphtheria bacilli.

Animals↗
PubMed1979

Immunoprecipitation and partial characterization of diphtheria toxin-binding glycoproteins from surface of guinea pig cells.

125I-Labeled membrane glycoproteins that specifically interact with diphtheria toxin and CRM197 protein--but not with diphtheria toxoid, fragment A of diphtheria toxin, or cholera toxin--were detected by use of the lactoperoxidase labeling technique followed by an immunoprecipitation system. These glycoproteins, which adhere to lentil lectin-Sepharose columns, are present on the surface of diphtheria toxin-sensitive guinea pig lymph node cells but are completely lacking on the surface of diphtheria toxin-resistant mouse L cells. The major 125I-labeled glycoprotein that interacts with diphtheria toxin exhibits anomalous behavior, characteristic of glycoproteins, when analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. This demonstration of the biochemical nature of specific diphtheria toxin binding membrane components raises the possibility that the detected components are diphtheria toxin receptors.

Animals↗
PubMed1977

[Diphtheria epidemic in eastern Switzerland in 1974].

A diphtheria epidemic in the eastern part of Switzerland in 1974 and the measures which were taken for its management and eradication are described. In particular it is pointed out that at present diphtheria displays atypical clinical symptoms in Europe, a fact that renders the diagnosis very difficult in many cases. Therefore, it is important to perform a throat swab in every patient with suspected diphtheria; it is also necessary to explicitly require a search for C. diphtheriae. The early recognition and early treatment of diphtheria with penicillin or erythromycin is of the utmost importance in order to avoid neurological and cardiac complications. With regard to the management and eradication of a diphtheria epidemic, the most important measures are rapid antibiotic protection of all contacts and a widespread immunization of the population. Vaccination of adults with a DiTe vaccine containing a reduced amount of Di-toxoid is recommanded.

Adolescent↗
PubMed1976

Isolation and partial characterization of a corynebacteriophage beta, tox operator constitutive-like mutant lysogen of Corynebacterium diphtheriae.

We have isolated and partially characterized a beta-phage mutant lysogen of Corynebacterium diphtheriae, C7(betatoxct1+), which is partially insensitive to iron inhibition of diphtheria toxin production. tox expression by C7(betatoxct1+) was found to be partially constitutive. In the presence of concentrations of iron that almost completely inhibit the expression of diphtheria toxin by the wild type, C7(beta), the level of toxin production by C7(betatoxct1+) was found to be at least 25 times that of the parent. The purified tox gene product of C7(betatoxct1+) was immunologically and electrophoretically identical to, and equally as toxic as, diphtheria toxin purified from C7(beta). In addition, the partial N-terminal amino acid sequence was found to be identical to diphtheria toxin. This data strongly suggests that the mutation allowing for the constitutive expression of tox in C7(betatoxct1+) is outside of the structural gene. Furthermore, the constitutive expression of diphtheria toxin was found to be cis dominant in the double lysogen C7(betacrm45+/betatoxct1+). The data presented is consistent with the existence of a tox operator locus.

Bacteriophages↗
PubMed1977

[The species C. diphtheriae].

Corynebacteria (C. diphtheriae var. gravis, mitis, minimus, intermedius, C. belfanti, C. ovis, C. ulceraus) producing diphtheria toxin are found as variants sharply differing from one another morphologically (from long branching rods to coccobacilli), culturally, biochemically and by other signs. The toxin synthesis in them was determined by genetically heterogeneous prophages tox+; tox+ virus exchange is possible between the corynebacteria. Since production of specific toxin, the cardinal sign of C. diphtheriae species, is connected with the genoms of genetically heterogeneous viruses tox+, the circle of whose hosts is very wide, it can be supposed that there is no genetically homogeneous taxonomic category "diphtheriae species". Several species of corynebacteria--lysogenized (toxigenic) or capable of being lysogenized (nontoxigenic) with tox+ viruses are included into the composition of the corynebacteria groups which medicine considers as "species" for over 80 years. A possiblity of becoming a diphtheria causative agent is determined by the capacity of corynebacteria to become infected with the circle of viruses tox+ the DNA of which can become stably integrated with the gene of this bacterium. The mentioned approach to taxonomy is possibly applicable to microorganisms in which the pathogenicity signs (the toxin) were determined, as in C. diphtheriae, in the virus genoms (Bac. botulinus).

Bacteriophage Typing↗
PubMed1978

[Identification of Corynebacterium diphtheriae by Way of Immunofluorescence (author's transl)].

The immunofluorescence technique (IF) will be demonstrated as a time-saving method for identifying Corynebacterium diphtheriae. In three test-series the IF-test was performed on 74 strains of C. diphtheriae which had been isolated in a small case of epidemic in Gelsenkirchen, on 4 strains of diphtheroids and on some strains to be found in the nasopharynx. All of these strains had been taken from blood agar, 69 toxinogenic strains of C. diphtheriae showed a clear, plainly reproducible fluorescence (Fig. 1). The diphtheroids and the other strains tested could be clearly differentiated from C. diphtheriae as a consequence of absent fluorescence of the cell wall. Because of morphological changes effected by potassium tellurite on C. diphtheriae smears made from tellurite media proved themselves to be inappropriate for the IF-test. Swabs from carriers of bacilli were not available for our IF-test. The results obtained from the blood agar, however, show that the IF-technique has to be considered as an improvement and a broadening of diphtheria diagnostics. New prospects present themselves for effecting the long aimed-at rapid diagnosis within a few hours.

Corynebacterium diphtheriae↗
PubMed2025

Analysis of novel zinc-binding proteins in the cell wall of Corynebacterium diphtheriae.

UNLABELLED: Zinc is a critical nutrient for all living organisms, including bacterial pathogens such as Corynebacterium diphtheriae, the causative agent of the severe human respiratory disease diphtheria. As such, zinc acquisition is essential for many pathogens to cause disease. We previously showed that the zinc-regulated ABC transporter encoded by the znu locus is one of several zinc uptake systems that support the growth of C. diphtheriae in zinc-limited medium. In this study, we examine the function and cellular localization of components encoded by the znu gene cluster, which includes the ZnuABC transporter and the novel membrane and cell wall proteins ZnuE, ZnuF, and ZnuG. Deletion of znuE results in reduced growth in zinc-limited media, suggesting a role in zinc uptake. While the growth of znuF and znuG mutants was not affected in zinc-limited medium, deletion of these two genes in a mutant also lacking the znuABC transporter restored growth to wild-type levels, suggesting that ZnuF and ZnuG exert an unusual modulating effect on zinc import. ZnuE, ZnuF, and ZnuG possess a unique motif that is associated with Zn binding as demonstrated by thermal shift assays, targeted mutagenesis, and structural analysis. Although ZnuF and ZnuG are both present in the cell wall, only ZnuG contains a sortase recognition signal that is critical for localizing proteins to the cell wall. Furthermore, ZnuF localization does not require any of the six known sortase enzymes in C. diphtheriae, suggesting a novel localization mechanism. IMPORTANCE: Zinc is a critical nutrient required by many bacterial pathogens. While the function of multiple zinc importer systems has been previously characterized in Corynebacterium diphtheriae, the transporter encoded by the znu gene cluster includes components not found in other metal transport systems. In this report, we examined the roles of three components of the znu gene cluster, ZnuE, ZnuF, and ZnuG, and show that these proteins all possess a putative zinc-binding domain and have varying effects on growth in zinc-limited medium. Additionally, ZnuF uses a novel mechanism for cell wall localization. This study further expands our understanding of C. diphtheriae zinc import and points to a potentially novel mechanism for the localization of cell wall proteins.

Corynebacterium diphtheriae↗
PubMed1976

[Minor diphtheria epidemic in a Cologne children's home (author's transl)].

Between May and July 1972, 12 children aged from 7 to 14 were admitted to the Cologne University Children's Hospital suspected of having diphtheria. In 10 cases the tonsils or pharyngeal cavity were affected. One case of wound diphtheria and one of nasal diphtheria were observed. The clinical suspicion was confirmed in 8 of 12 cases by detection of the pathogen Coryne-bacterium diphtheroides mitis. 11 patients were discharged from the hospital after being treated for between 2 to 6 weeks, but 5 of them needed ambulant cardiac observation. One patient died of malignant diphtheria with symptoms of cardiovascular failure. He had not been treated specifically for 1 week at first. Not one of the 12 patients had been satisfactorily immunized by active inoculation with diphtheria toxoid.

Adolescent↗
PubMed2026

Molecular epidemiology and antimicrobial resistance determinants of Corynebacterium diphtheriae causing infections in Karachi, Pakistan, 2023-2024.

OBJECTIVES: Diphtheria remains endemic in Pakistan, with cases increasing following the COVID-19 pandemic despite ongoing vaccination programs. This study analyzes the genomic diversity, virulence, and antimicrobial resistance patterns of pharyngeal diphtheria strains collected during the Karachi outbreak. METHODS: Corynebacterium diphtheriae isolates from a tertiary care hospital laboratory in Karachi (August 2023-October 2024) were included. Antimicrobial susceptibility testing and whole-genome sequencing of phenotypically confirmed isolates were performed. Phylogenetic and bioinformatics analyses were performed using diphtOscan and AMRFinderPlus tools. RESULTS: A total of 47 pharyngeal C. diphtheriae isolates were included. The median age of patients was 7 years, and the male-to-female ratio was 1.6:1. The tox gene was present in 89.4% of isolates, while only 29% (n = 13/45) demonstrated toxin production. Genomic analysis identified 10 sequence types; ST384 and ST698 were most prevalent. Phenotypically, 34% (n = 16) were resistant to both erythromycin and penicillin, and 49% (n = 23) were multidrug-resistant. The most prevalent resistance genes were sul1 (100%), erm(X) (76.6%), and pbp2m (51.1%). CONCLUSION: Circulation of diverse C. diphtheriae strains with alarming antimicrobial resistance underscores the need for genomic surveillance to evaluate transmission trends. We further highlight the limitations of the Elek test in detecting toxin production and the need for improved diagnostics in low- and middle-income countries.

Antimicrobial resistance↗
PubMed1978

Antitoxin responses in the elderly to tetanus-diphtheria (TD) immunization.

A high per centage of reported cases of tetanus and diphtheria in the United States occurs in persons over 60 years old. The sera of 69 elderly persons, mean age 80 years, were tested for prevalence of tetanus and diphtheria antibodies, and only 51% and 59%, respectively, had protective levels (greater than or equal to .01 AU/ml). In a prospective study 27 elderly volunteers were given 0.5 ml tetanus-diphtheria (Td) toxoid twice, seven months apart. Before toxoid 26% and 59% of persons had protective antitoxin levels against tetanus and diphtheria. After one dose the per cent protected rose to 42 and 88. After the second dose all persons immunized had protective levels. No subjects had significant side effects after either dose. These data demonstrate that many elderly persons lack protection against tetanus and diphtheria and document that two doses of Td toxoid would confer immunity to virtually all such persons.

Aged↗
PubMed1978

Evidence that the regulation of diphtheria toxin production is directed at the level of transcription.

It has been known for several decades that iron inhibits the production of diphtheria toxin by Corynebacterium diphtheriae by preventing expression at maximal levels. We examined the inhibition kinetics of toxin production after the addition of either iron or rifampin to iron-limited cultures of C7 (betatox+). Iron-mediated inhibition of toxin production was found to be linear within the range of 16 nM to 16 micron. The inhibition kinetics following the addition of iron or rifampin was almost identical. [3H]RNA extracted from iron-limited toxigenic C. diphtheriae was found to hybridize to a greater extent to corynephage beta DNA than either [3H]RNA extracted from toxigenic C. diphtheriae before the onset of toxin production or [3H]RNA extracted from nonlysogenic, nontoxigenic C. diphtheriae.

Corynebacterium diphtheriae↗